Machine tool



,l Nv. 12, 1935. G. T. HUXEORD ET Al.

MACHINE TOOL Filed June 13, 1951 7 Sheets-Sheet 1 BY mu 0 A TORNE y Nov.l2, 1935.,

G. T. HUXFQRD r-:T AL.l

MACHINE TOOL 7 Sheets-Sheet 2 Filed June 13, 1931 NOV. 12, 1935. G, T,HUXFORD ET AL v 2,021,066

MACHINE TOOL Filed June 13, 1931k 7 Sheets-Sheet 3 ATTORNEY Nov. 12,1935. G. T1 HUxFoRD ET AL I 2,021,066

MACHINE TOOL Filed June 15, 1951 7 Sheets-Sheet 4 A TTORNE Y Nov. 12,1935. G. T. HuxFoRD Er AL MACHINE TOOL Filed June 13, 1951 7Sheets-Sheet 5 Nov. l2, 1935. G. T. HuxoRD ET Al.y

MACHINE TOOL Filed June 15, 1931 '7 Sheets-Sheet 6 NOV. 12, 1935. lG,'THUXFORD AL 2,021,066

MACHINE TOOL Filed June 13, 1931 7 Sheets-Sheet '7 m aa A TTORNEYPatented Nov. 12, 1935l UNITEDI STATES PATENT oFFlcE,

MACHINE TOOL George T. Huxford, Providence, Frank E. Strat- Y ton,Cranston, and Paul G. Heinemann, Provl- I dence, R. I., assignors toDiamond Machine Co., Providence, R. I., a corporation of Rhode IslandApplication June 1s, 1931, serial Nn. 544,122

1s claims. (ci. 51.42)

Our invention relates to improvements in grinding machines or similartypes of machinetools.

Our invention includes a mixed electric and hydraulic system for feedingthe work and tool l5 thereof the desired amounts relative to each otherfor the grinding operation. Our invention includes a table vfor holdingthe Work, a fluid system including uid o-perated means for reciprocatingthe table which preferably includes a cylinder with suitable pistons, apump, preferably a uni-directional pump for supplying fluid to saidmeans and preferably a movable valve controlling the flow of iiuid insaid system operable to change the direction of circulation of fluid insaid sys-r tem to alternately move said table in opposite directions,said means usually preferably including a slidable double acting doublepiston valve. We also preferably employ means to vary the speed ofvfluid flow which in one embodiment of our invention comprises anadjustable valve to regulate the feed of iiuid from the pipe in thesystem and in another embodiment of our invention comprises anadjustment `to the pump to regulate the flo-w of fluid therefrom. Wealso preferably provide a pressure relief valvewhich functions as asafety valve to release an excess pressure in said system for any reasonand a manually controlled bypass for interrupting the flow of uidthrough said Isystem to stop said table at any desired portion of itsreciprocation cycle. Our invention specifically relates to improvementsin thel electrical system for actuating said valve or otherreciprocating means to change the flow of fluid through the system andfor this purpose we preferably extend the piston of the Valve and haveit alternately drawn in opposite directions by two oppositely disposedsolenoids or other electrical means andwe also provide means preferablycomprising a novel type of adjustable dashpotalso preferably directlyattached l to said valve piston to cushion the `valve at vthe end of thestrokes and said cushioning means or dashpot is preferably madeadjustable in order to vary the time interval between the strokes oftable reciprocation, namely, the Vdrag dwell or delay at the end of thetables strokes. tool is preferably mounted on said machine independentlyof the table to contact the reciproeating work.. Any suitable type ofmeans may ferred embodiment we preferably provide a type of meansincluding a pawl and ratchet' for feeding the tool substantially atright angles to the ploy a solenoid or other electrical means foractuating this type of mechanical means, the solenoid moving the pawltoactuate the ratchet to feed the tool the desired amount. An electriccircuit for actuating said table reciprocation actuating sole- 5 noidsand said tool feeding solenoid'is provided and we preferably include insaid circuit a magnetic switch for alternately operatingv the valveactuating solenoids and simultaneously therewith y actuating the toolfeeding solenoid. We provide 10 switch means automatically actuated bythe table to actuate the magnetic switch to actuate the proper slidablevalve solenoid and actuate said tool solenoid substantially at the endof each table stroke. In our preferred embodiment the 15 switch meansautomatically actuated by the table completes the circuit tosimultaneously actuate the magnetic switch to actuate the slidable valvesolenoid and the tool solenoid atv substantially 1 the ends of thestrokes and we also provide switch 20 means actuated by the valve orother reciprocating means employed at substantially the completion ofits change of position to break said circuit, thereby insuring thatthere will be enough electricity to complete the desired feeding of the25 tool and the change in valve position until such change has actuallytaken vplace and when the transition is accomplished that there will beno electricity in the circuit to burn out the solenoids or otherwiseimpair the electric systems.

` One important feature of our invention resides in the means we employ'fc-r breaking the circuit to'cut off all current preferably to changethe position of the valve in case for any reason lsource of supply Theusual reciprocating work predetermined amounts relatively to the workandWe preferably also emthe table should reciprocate more than its desired35 normal stroke, said means comprising limit switches in the electricalcircuit adapted to break said circuit to stop said movement at a placebeyond the normal .path of movement of said reciprocating table. f

A further feature of `our invention relates to the improved type of`automatic oiler we employ for oilingthe table ways fedfrom thehydraulic These and such other objects of our invention 45 as mayhereinafter appear willbe best under- 'stood from a, description of theembodiments thereof shown in the accompanying drawings. be provided toactuate the tool, but in our pre- In the drawings, Fig.` 1 is aperspective view of 50 a grinding machine constructed in accordance withour invention.

Fig. 2 is a diagrammatic skeleton view ofthe. operative parts thereof. fFig. 3 is a diagrammaticvlew of the connec- 55 60 justable thereon sothat theyvmay be-widsiifi'I f. ready'- reach of Vtheoperative';standing'inffrcn s .vf'gof the reciprocating slide 36.adjacentfthe gr1'ic;li .l

tionsfor theelectric system in one position of the table.

Fig. 4 is a diagrammatic View of the connections for the electric systemin another position 5 of the table.

Fig. 5 is an enlarged sectional view of the pressure relief valve,adjustable uid flow regulating valve and bypass valve we employ in theembodiment of our invention shown in Fig. l.

Fig. 6 is a sectional view taken along the line 6-6 of Fig. 5.

Fig. 'lis a plan view partially shown in section of the tool advancingmeans and its connected solenoid.

Fig. 8 is a cross-sectional view taken along the line 8-8 of Fig. 7. i

' Fig. 9 is a perspective view of a grinding machine equipped with thepreferred embodiment of our invention.

Fig. 10 is a diagrammatic skeleton view of the operative parts thereofsimilar to Fig. 2.

Fig. 11 is a cross-sectional view taken through the table and Ways toshow the novel type of automatic oiler for the table Ways we preferablyemploy.

Fig. 12 is a view of the electric circuit generally similar to Fig. 3 ofthe embodiment of our invention shown in Fig. 9 showing the table in oneposition.

Fig. 13 is a view of the electric circuit generally similar to Fig. 3,of the embodiment of our invention shown in Fig. 9 showing the table inanother position.

In the drawings, wherein like characters of reference indicate likeparts throughout, 20 generally indicatesa grinding machine constructedin accordance with our invention. We will first describe the embodimentof our invention shown in Figs. 1-8 and then note the points ofdifference between that embodiment of ourA invention and our preferredform of invention shown in Figs. 9-13. Said grinding machine 20 includesthe usual frame 22 having the ways 24 on which the grinding wheel tableor other reciprocatable means 26 is reciprocatably mounted as usual. Inour preferred embodiment the grinding wheel or *cl'r tool employed 28 ispreferably mounted on the forward extension 30 of said frame 22 in frontof said reciprocating table 26. The grinding wheel 28 is provided withsuitable means (not shown) for feeding it relative'to the work, saidmeans being actuated by the shaft 32. A water trough 34 normally extendslongitudinally of the machine underneath the grinding wheel 281. The

slide 36 reciprocates in front of the frameand is driven by the table 26by the medium of reduction gearing 38 extending through the trough 34.-It is obvious therefore that the slide 35 slides in front ofthe frame 22and has the dogs 411,941-A .'Lzing wheel'28 and that said dogs 40 maybereadily adjustedby an operative without his moving theV full lengthofthe grinding machine, said feature forming the subject matter of adifferent application, Serial Number 536,539, led May 11th, 1931 uponwhich Patent No. 1,899,362 was granted February 28, 1933, of Frank E.Stratton, one .lof-.the

' 70 joint inventors herein. lThe dogs I4I! actuate'the tripping lever42 which will be described in detail later. We preferably also employthe-pivoted sediment tank 44 which is formed to strain the sediment fromthe coolant and is suitably pivoted at a point on the frame 22, 'so thatit may be pivoted outwards for removal of sediment therefrom.

The table 26 in both the embodiments is driven by the piston 46 whichreciprocates in the cylinder 48 and which is attached to a suitable lug50 5 depending from one end of the table 26. The fluid system forreciprocating the table includes the reservoir 52 and the preferablyuni-directional pump 54 suitably driven by the motor 56. The flow to theoperating cylinder 48 is controlled 10 by the slidable valve 58interposed in said fluid system. The fluid is drawn from said reservoir52 to said pump 54 by the connecting pipe 68 and it isV discharged fromsaid pump 54 through the medium of the valve inlet pipe 62. The slidable15 valve 58 includes the cylinder 64 and the piston 66 provided with thespaced pilot piston heads 68 and l69 therein. The valve inlet pipe 62discharges substantially centrally of the cylinder 64.

A pipe 12 discharges from a point approximately 20 one-half the distancebetween the center and end of said cylinder 64 into one end of theoperating cylinder 48 and another pipe 10 discharges from approximatelythe same point on the opposite side of said valve cylinder 64 to theopposite end of 25 said operating cylinder 48. The valve cylinder 64 isprovided with the discharge pipes 16 and 14 respectively near each endthereof which converge to a common discharge pipe 18 discharging intothe reservoir 52. The piston 66 is automati- 30 cally moved in a mannerto be explained at the end of the table strokes.

When in the position shown in Fig. 2 uid flowing from the pump 54 isforced centrally into the valve cylinder 64 and due to the then posi- 35tion of the pilot piston heads 68 and 69 flows upwardly through the pipe12 to force the piston head 46 in the cylinder 48 to the left andthereby automatically moving the table 26 to the left by the medium ofits connection piston rod 41 and 40 lug 50 thereto. It is thus obviousthat as the piston head 46 is being forced to the left that fluid willbe discharged from the cylinder 48 by the opposite side of said piston46 through the pipe 16 into the left hand end of the pilot cylin- 45 der64 and back through the discharge pipe 14 and through the pipe 18 to thereservoir 52. When the table 26 has completed its maximum movement tothe left a dog 40 will trip the lever 42 to actuate the electricalsystem in a manner 50 to be explained to move the piston 66 of the valveand hence the pilot piston heads 68 and -69 to the opposite position sothat fluid will be discharged from the valve cylinder 64 through thepipe 10 into the left hand end of the operating 55- cylinder 48 to forcethe piston head 46 and hence table 26 to the right and that fluid willdischarge from said operating cylinder 48 through said pipe 12 and asthe piston head 69 is moved over centrally of. said valve cylinder 64through the right 60 hand end` of the valvecylinder 64 out tothe'discharge pipe 16 'andf'through the pipe 18 to the 'reservoir 52. -Itis thus" obvious that the fluid system will operate to first push' thetable 26 to .the left and at the end `o1' the table stroke when 65 theposition of thefvalve piston heads 68 and 69 are changed will thenoperate to pull it to the right.

Our improved hydraulic system, however, also includes' means to vary thespeed of Vfluid ow 70 through the system. In our preferred embodimentand as more particularly shown in Figs. 2 and 5 said means comprises anadjustable conical valve head 86 threadedly adjustable by means of thethumb screw 82 from voutside of the ma- 75 2,021,063 chine relativeto'the cooperating downwardly" tapering conical seat 84. It is thusobvious that when the thumb screw 82 is turned to raise the position ofthe valve head 80 relative to said valve seat 84 that more fluid will beadmitted through the inlet pipe 62 tothe valve cylinder 64. The valvehead adjusting rod 86 is threadedly adjusted in a suitable gland 88 withpacking 89 extending opposite said inlet pipe 62 (see Fig. 5). In caseanything should be the matter with the fiuid system we provide twobypasses from the inlet pipe directly back to the reservoir. One

includes the pressure relief valve 90, comprising the valve head 92normally held in position by system 'of the fluid from the inlet line 62back to the the diaphragm 94 against the valve seat 96. A spring 98normally urges said diaphragm 94 to urge said valve head 92 `downwardsagainst the valve seat 96 and the tension on the upper end of saidspring 98 is made 'adjustable by the means of an adjusting thumb screw|00, also threadedly adjustable within an extension from said inlet pipe62. It is obvious that when pressure in said system builds up greaterthan the pressure of the spring 98 against the diaphragm 94, that itwill push the diaphragm 94 upwards thus raising the valve head 92 fromits seat 96 and permitting the ovf of fluid from the bypass |02 fromsaid inlet pipe 62 through the now openV valve 92-96 and back tothereservoir through the discharge pipe |04.

We also preferably provi-de a manually controlled bypass forinterrupting the ow of fluid through said system to stop said table atany desired portion of its reciprocating cycle. Said bypass valve isalso constructed to automatically cut off the current from theelectrical system simultaneously with bypassing the fluid from the inletback to the reservoir. In our preferred embodiment said bypass valve isconstructed as follows. A bypass line |06 leads from said inlet pipe 62to the bypass valve |08. As shown in Figs. 5 and 6 our preferredembodiment of bypass valve comprises a rotary valve head ||0 provided'with the sector shaped walls ||2 which may be rotated to a positionclosing-the bypass line |06, thereby permitting the fluid to normallyflow through the system through the usual inlet 62 and which may berotated by means of the handle ||4 so that the open portion ||6 of saidrotary valve head ||0 will be in a position to permit the flow of fluidthrough said bypass valve |08 and out through the discharge pipe ||8 tothe reservoir 52. The valve head ||0' is mounted on the rod |20 to whichthe handle ||4 is attache-d. Said rod |20 is preferably extended and hasmounted thereon ed on opening of said valve |08 to open the switch |24to break the circuit in the electrical 260 simultaneously with thebypassing reservoir 52 through the pipe |06, valve |08, pipe H8. Whenthe valve |08 is closed, the cam |22 moves to a position to permit thecontact arm |23 to close the switch |24 to complete the circuit. Thespring actuated contact arm |23 on removal of said cam |22 moves to aposition to complete the circuit at all times when said arm v |23 is notcontacted by the cam |22.

The improved embodiment of our invention shown in Figs. 9 to 13 isprovided with a slightly different embodiment of pressure relief valve90 provided with the adjustable turning screw |00".

This, however, preferably has a hexagonal head so as to be turned by amember for the initial adjustment thereof. InV this embodiment anexously raising the horizontal arm the cam |22 adapt- In this embodimentthe pump 54 itself is provided with means for controlling the rate'offlow therethrough, said means being adjustable by means of the turninglever 82. In all other respects the hydraulic systems in bothembodiments are similar.

The electrical system includes the two'opposite` disposed solenoids |38and |40, the solenoid |38 being operative to draw the valve piston rod66 to the right to permit the table to be pulled to the left, and thesolenoid |40 being operative to move the valve piston 66 to the left topermit the table to be pushed to the right. The solenoids |38 and |40are controlled by the magnetic switch |42 which magnetic switch alsocontrols the cross feed solenoid |44,` which operates to feed the toolthe desired amount forward at the end of each table stroke. Whenever thearmature of the solenoid |44 is actuated it operates to raise theplunger I|46 upwards. IThe plunger |46 is mounted on an arm |48pivotally mounted at |50. Said arm |48 also has the rod |54 verticallymounted thereon and the upper end thereof is attached to an arm |56which has on its opposite end the collar |58 surrounding the shaft |60on which the ratchet |62 is mounted. The pawl |64 is pivotally mountedon the'arm |56 in a manner to engage the ratchet teeth. Whenever acurrent flows through the solenoid |44, theplunger |46 is raised upwardagainst the force of gravity, thereby simultane- |48, the vertical rozl|54, the outer end of the arm |56 and correspondingly the pawl |64, sothat the pawl |64 will engage in the ratchet teeth |62 to rotate ,theratchet hence the shaft |60 the desired justable stop screw |68, thepawl |64 on its downward movement merely sliding lightly over theAratchet teeth |62. It is apparent that the throw of the number ofratchet teeth that the pawl will be jerked forward on each actuation ofthe solenoid may be adjustably varied by means of Athe adjusting screw|68. The shaft |60 drives the traversing shaft 32 through the medium ofthe connecting bevel gears |10 and |12. As shown in Figs. 1, '1 and 8the stop screw |68 may have an adjusting nut therefor broken into twoparts operating at right angles and connected by the bevel gears |14 and|16, the adjusting gear |16 on the rod |18 being adjusted by the turninghande to vary the amount that the head |82 of the stop screw |68projects upwardly to abut the arm |66 projecting laterally from saidvertical rod |54. The portion o'f the arm |66 which abuts the upper endl82 of the stop screw |68 may comprise a rod |84 resiliently mountedthereon. The pawl |64 may be urged against the ratchet teeth by thespring device |88 shown in Fig. 8. Itis also apparent that the tool maybe traversed by the means of the operating' wheel |88, also mounted onsaid shaft |60. The dial |90 is mounted around said shaft |60 and iscontiuously held against it to rotate therewith by means of the frictionspring |8I. It may, 75.v

however, be adjusted relative thereto the spring |9| yielding for thispurpose. It is :also obvious that if it is desired to move the pawl |64away from said ratchet teeth |62 that the pawl may be pivoted againstthe pressure of the spring until the pointed end |92 engages theprojection |93 on the pawl to hold the pawl in raised position. It isapparent that the pawl may again be brought into position to contact theratchet teeth merely by pressingdown on it to overcome the pressure inthe spring |85 in the spring device |66.

As stated, we provide cushioning means for the slidable valve 58preferably adjustable to vary the dwell between movements of thereciproeatable means in opposite directions. In our preferred embodimentsaid cushioning means |94 is directly attached to the valve piston 66 soas to function substantially at the ends of the tables strokes. Saidcushioning means includes the double acting clash pot provided with theelongated horizontal chamber |95. An adjustable egress valve |96 isprovided at each end of the chamber and a check ingress valve |98 isalso provided at each end of said chamber. The valves |96 and |98 arepreferably formed in the wells 202 and 204 at each end of the chamber.The adjustable egress valve preferably is formed as follows: 'I'he upperend/of each respective well 202 and 204 is provided with the preferablyupwardly extending frusto-conical valve lseat 206 near the upper endthereof. 'I'he movable member 208 is provided including the thumb screw2| 0 vertically adjustable in said dash pot casing and having the innerend thereof firmly secured to a member having a irusto-conical valvehead 2 I2 adapted to cooperate with the frusto-conical valve seat 206 tobe adjustable relative thereto by. means of moving the thumb screw 2|0.It is thus obvious that by adjusting the valve head 2I2 relative to thevalve seat 206 that an adjustable diverging annular discharge passagebetween said valve seat and valve head is formed discharging into thelower portion of thewells 202 and. 204 and into the channel 200 leadingfrom the base of the well 202 to the base of the well 204. The movableportion 2|4 of said movable member within each respective well isprovided with a channel 2|6 leading from the base thereof andcommunicating with .said channel 200 and discharging upwardly within the.center portion of each valve head 2|2.' The thumb screws 2|0 comprisemeans operable from without said dashpot-tol move said movable portionto adjust the' position of the valvel head relative to the valve seat.The check valve -lincludes the valve seat 2.15V formed 'in the upper endof the discharge passage 2|6` and the valve head therefor comprisesthe.bal1f2l8 preferably constrained to move in a vertical position by thecage 220 also adjustable from without said dashpot and having thefscrewbase`222 provided with the operating slot'.224 'threadedly adjustablewithin a portion of said dashpotabove said check valve seat 2|5. 'Ifdesired the channel 200 may be provided with the supplementary channel226 communicatingwith the center portion of the `chamber |95. l Thepiston 228 is provided to reciprocate within said chamber |95 and isvconnected to the valve piston rod 66 .to move horizontally in oppositedirections simultaneously therewith, by means of the lever 230 pivotedwithin said casing at 232 and having the power arn 234 attached to anend of said piston rod 66 and thework arm 236 thereof comprising a ball235 contained within a channel 231 in the center portion of said piston228. It is thus apparent that as said piston 66 is reciprocated by themovement of the slidable valve through the action of the solenoids 38and |40 that said pis- 5 ton 228 will be forced simultaneously inopposite directions within said dashpot |95. As said dashpot piston 228is forced towards the left in the embodiment shown it" is obvious thatthe cushioning uid namely, preferably oil prefer- 10 ably provided fromthe reservoir 52 will be forced downwards through the egress valve |96to the lower portion of the well 202, through the channel ,200 into the'lower portion of the wel1- 204 and then through the channel 2|6 therein15 out through the check valve seat 2|5 in the upper end thereof andlifting the ball 2|8 in said opposite well 204 off its seat fordischarge of vfluid in the right hand end of the chamber from the well202. It is obvious that on reverse move- 20 ments of the piston the oilor other cushioning uid will be forced downwards through the adjustableegress valve |96 in the well 204 and out through the check valve |98 inthe well 202. It is also apparent that the speed of the cushioning 25uid ow may be varied by varying the adjustment of the opening in theadjustable valve by turning the thumb screws 2|0 and that by soadjusting the speed of fluid ow in the dashpot in the embodiment shownin Figs. 9-12 particularly 30 the cushioning time interval or dwellbetween movements of the table in opposite directions may be adjustablyvaried.

'From the foregoing description and the drawings, it is apparent thatthe various means may 35 be broadly dened and identified as follows:table 26 is a reciprocatable means; piston 46 with its piston rod 41operating in hydraulic cylinder 48 constitute an unsymmetricaliluid-operated reciprocating means; the reversing .valve 40 piston rod66 is clearly a movable part actuated by the solenoids |38 and |40which, with their switches 264 and 266 and relay means |42, constituteelectrical means broadly; .reversing 'valve piston 66 in its cylinder 64is a duid-flow 45 4reversing means and with the above electrical meanscomprises reversal controlling means; table dogs 40 trip the lever 42and actuate switches 264 and 266 and, as above brought out, broady areswitch means; cushion means |94 50 attached to valve piston |66 includesa doubleaction dash-pot with chamber |95 and comprises a means forcontrolling the speed of reversal; the area of piston rod 41 mustbe'subtracted from piston 46 in one direction to obtain 55 the neteiective area, thus causing a lack of hydraulic symmetry, said lack ofhydraulic symmetry bein'ggenerally used to provide a slowspeed workingstroke and a high-speed return stroke; valve 80 is a fluid-flow speedcontrol 60 means which determines the speed of the working stroke andhence, normally, also that of the return stroke; pressure-relief valvetruly cooperates with the above to determine the maximum accelerationthat can be given table 26; 65 table 26 moves over a normal pathdetermined by the position of dogs 40, said table constituting a meanstocarry work which isacted upon by grinding wheel 28; grinding wheel 28and table 25 thus respectively constituting means func- 70 tioning'with' a reciprocatable means; in combination with the above is thecross feed solenoid |44 controlled by magnetic switch |42 operating tofeed the grinding wheel 28 the desired amount forward at the end of eachtable stroke-which 75 broadly constitutes feeding means for thefunctioning means.

Recapitulating: a single fluid-flow speed control means 80 is providedfor the unsymmetrical fluid-operated reciprocating means 46, 41 and 48which operates table 26 slowly during its working stroke in onedirection and rapidly on its return stroke in the other direction; table26 governs its own reversal by dogs 40 operating electric switch means|42 at the opposite ends of its normal path; pressure-relief valveeffects the maximum amount of dwell of table 26 during its reversalsdepending somewhat upon the position of the fluid-how speed controlmeans 80; during this dwell, the solenoid-operated feeding means |44 isoperated to feed grinding wheel 28 towards theA work carried on table26; cushioning means |94 controls the rate of operation of reversingvalve 66 independently in opposite directions, reversing valve 66 beingoperated by solenoids |38 and |40, to give the desired shocklessreversal of reciprocating means 26. Thus from the rsum contained inthis, and the preceding paragraph, it is apparent that all of theabove-mentioned means work together in true combination for theachievement of a shockless reversal of a work-carrying table,reciprocated over a normal path by an unsymmetrical fluidactuated means(by individually adjusting the dwell at the opposite ends of the path)and the feeding of work-removing means toward the work during theperiods of dwell thus provided.

'As stated we also provide an automatic oiler 240 for oiling the ways 24of the table shown in *more detailv in Figs. 2, 10 and 11. Said oiler240 includes the chamber 244 suitably fed by the pipe 246 connected tothe discharge pipe 18 in said fiuid system. Said chamber is preferablyprovided with one or more drip holes 248 leading to the pipes 250 whichdischarge in the respective ways 24. Between said drip holes 248 andpipes 250 we preferably provide the sight drip gauges 252 provided withtransparent sides so that the amount of oil dripping therethrough may.be visible from without. We also provide manually adjustable means foradjustably closing said drip holes 248 from .without comprising thethumb screws 254 having pointed ends adjustable within said drip holes248 by means of the heads 256 operable from without said casing 244.said thumb screws 254 being threadedly adjustable in holes in the topwall of the casing for said chamber 244.

As stated hitherto, we preferably control the reciprocation of thereciprocatable means by .suitable electric means and in our preferredembodiment preferably provide a suitable electric circuit with theconnections about to be described for moving the slidable valve 58 toreciprocate this reciprocatable means. The embodiment of the electricalcircuit for actuating the valve 58 in the embodiment shown (in Figs. 18) is diagrammatically illustrated in two positions in Figs. 3 and 4 andthe electrical circuit for actuating the preferred embodiment of ourinvention shown in Figs. 9-13 is diagrammatcally illustrated in Figs. l2and 13.` In general the embodiments of these two inventions are similar,the embodiment of the invention shown in the yelectrical circuit showninFigs. 12 and 13, comprising a few specific improvements over thatshown in Figs. 3 and 4. We provide the solenoids i |38 and |40 forcontrolling the movement of 'the reciprocatable means or table 26 ineach of the specific embodiments by specifically controlling the valve58 for controlling the reciprocating means 46, 48 for reciprocating thereciprocatable means or table 26. As also stated we provide meansmounted on said machine independently of the reciprocatable means andtable 26 such as the grinding wheel or tool 28 to function with saidreciprocatable means. As stated we also provide means for feeding saidfunctioning means relative to the reciprocating means, namely the pawland ratchet connection hitherto described and .we provide electrical.

means for' moving the feeding means in the direction to feed thefunctioning means or grinding wheel 28 relative to the work on thereciprocatable means 26. A cut-out switch |43 may be provided ahead ofsolenoid |44 so that cross feed mechanism may be worked manually orotherwise independently of the electric circuit. In our preferredembodiment we provide an electric circuit 260 for actuating saidelectrical means, namely the solenoids |38 and |40 for controlling thevalve and the solenoid |44 for advancing the feeding means for thegrinding wheel. Said electrical circuit preferably includes the magneticswitch |42 forv alternatively operating the reciprocatable meanssolenoids |38 and |40 and simultaneously actuating said functioningmeans actuating solenoid |44 and We also provide switch means 42automatically actuated by the reciprocatable means or table 26 foractuating said magnetic switch |42 to actuate one of the slidable valvesolenoids |38 or |40.

Said switch means 42 includes the operating lever 262 suitably pivotedin opposite directions by means of the dogs and adapted when piv- 35oted to the right to close the switch 264 connected to the electrical`circuit 260 and when pivoted in the opposite direction to close theswitch 266 connected to the electric circuit 260. In the embodimentshown in Figs. 3 and 4 said switches 264 and 266 are'held down by theposition of the operating lever 262 so long as it is held by either oneof the opposite disposed dogs. When either dog draws away from theoperating lever 262 the weight 268 will immediately operate to draw theoperating lever 262 to a vertical position away from the contactingswitches 264 or 266 and as the switches 264 and 266 are normally forcedto open position by the springs 210, they will immediately function tobreak the circuit when the operating lever is drawn away from it. i

For ease of description we will divide the main circuit 260 into varioussupplemental divisions.

.The magnetic switch |42 is operated by the thereon. The circuit 260 maybe conveniently divided for purposes of description into the main line282 which supplies the necessary current for operating the various partsof the circuit and is suitably connected to the various subcircuits in amanner to cause their operation. In Figs. 3 and 12 We have shown in fulllines the circuits which are actuated at the completion of the movementof the table 26 to the right to cause the functioning of the valve 58 tostart the movement of the table to the left and we have shown in Figs. 4and 13 the table at the end of its completion of its stroke tothe leftand actuating the circuit to start the actuation, ofthe valve 58 tocause the movement of the table to the right. The switch circuit 264"which is completed when the operating lever 262 has closed the switch264 is connected to the main circuit 282 so as to actuate the solenoid212 to pull the armature 216 towards the right as shown in Figs. 3 and12 to move the sets of contact plates 218 to the right to complete acircuit from the main line 282 through the line |38' for actuating thesolenoid |38 for pulling the piston rod 66 to the right to start pushingthe table 26 to the left and to also energize the circuit; |44 which issuitably connected through suitable contacts by suitable tie-ins in themagnetic switch to the main line 282 to energize the solenoid |44simultaneously with the venergization of the `solenoid |38 to energizethe plunger 46, to suitably actuate the feeding mechanism to feed thegrinding wheel forward the desired amount by means of the plunger |46.When the left hand dog 46 is moved away from the operating lever 262 theoperating lever will pivot to a vertical position, thereby permittingvthe automatic opening switch 264 to open breaking the circuit 264 andthus cutting off the current to the solenoid 212, the contact switchplate 218 being pulled to a neutral position by means of the weight 219thus breaking the circuit-to the solenoid |38 and solenoid |44. We haveshown in Figs. 4 and 13 what takes place at the end of the oppositemovement of the table 26. As the table 26 completes its stroke towardsthe left it p is obvious that the dog 40 will knock the operating lever262 over towards the left -to complete the circuit 266' shown in fulllinesin Figs.. 4 and 13 which in turn will actuate the solenoid 214 todraw the magnetic switch rod 216 to the left from its neutral positionand so that the oppo'- site set of plates 280 thereof may close acircuit to form av circuit from the main circuit 282 through the circuit|40' for operating the solenoid |46 to energize the solenoid |46 to movethepiston 66 to the left to move the valve 56 :to`start the movement ofthe table again to the right and simultaneously energize the solenoidcircuit |44' to feed the tool the desired amount forward during thedwell at this period of the reciprocation cycle by means of the sole--noid |44 and plunger |46 actuating the feeding mechanismheretoforedescribed. It is alsol apparent that when the dog 40" is moved away fromthe operating lever 262 that the operating v266 'operate to energizetheir respective circuits 264'and' 266 to energize the respectivesolenoids 212 and 214 of the main magnetic switch |42 to move italternately opposite the desired direction.I `We have found in practice,however, that it is not desirable to keep the various circuits energizedfor any longer period than is necessary for actually reversing thevalve, particularly in case the table should stop while in reversingposition. If the table stops in reversing position in the embodimentshown in Figs. 3 and 4 the current would be apt to burn out thesolenoids. In the embodiments shown in Figs. 12'and 13, however, this ispositively prevented for* as soon as vthe solenoids |38 and Mohavepiston 66 after it has changed in position in the i desired manner tocompletely deenergize respectively both the solenoid operating circuits|38' and |40 and the traverse mechanism operating solenoid circuit |44as soon as the valve piston 66 has shifted its position.` This has theadditional advantage of enabling the operative to know in whichdirection the table is heading if desired to start up near the end of astroke. The switches |24 for cutting off the current in the main line260 have already been described.

As stated hitherto we also provide in an electrical circuit forcontrolling the reciprocation of the reciprocatable means 26, limitswitches 290 located in said circuit preferably spaced beyond the normalpath of the movement of said reciprocatable means 26 and adapted tobreak said circuit 260 when for any reason the table 26 or otherreciprocatable means employed passes beyond the normal limit ofreciprocation thereby forming a safety device for completely shuttingolf the electric actuating circuit if the table should go beyond itsdesired path of reciprocating travel. `Said switches are connected tothe main line 260 in any suitable manner and preferably are of the selfclosing or self-opening type shown in switches 264 and 266.

It is understood that our invention is not limited to the specificconstruction shown andvthat various deviations may be made therefromwithout departing from the spirit and scope of the appended claims.

What we claim is:

1. In a machine tool, in combination, reciprocatable means,fluid-operated means for reciprocating said reciprocatable means, meansmounted on said machine independently of said reciprocatable means tofunction with said reciprocatable means, one of said means being adaptedto carry work and the other to act upon said work, means for feedingsaid functioning means relative to said reciprocatable means andelectrical means adapted tobe actuated by said reciprocatable 'means atsubstantially the ends of the reciprocatable means strokes forcontrolling the reversal of said fluid-operated reciprocatable means andfor moving said feeding means to simultaneously reverse the direction ofreciprocation and to feed said functioning means.

2. In a machine tool, in combination, reciprocatable means, a fluidsystem including uid operated means for reciprocating the reciprocatablemeans, a uni-directional pump for supplying fluid to said reciprocatingmeans, a slidable valve for reversing the flow of fiuid to saidreciprocating means operable vto change the direction of circulation offluid in said 'system to alternately move said reciprocatable means inopposite directions, two solenoids for actuating said valve alternatelyin opposite directions, means mounted on said machine independently ofthe reciprocatable means to function with said reciprocatable means, oneof said means being adapted to .carry work and the other to act uponsaid work, means for feeding said functioning means relative tothereciprocatable means, a solenoid for moving said feeding means in adirection to feed the functioning means, an 'electric circuit foractuating said solenoids including a magnetic switch for alternately,operating the said valve actuating solenoids and simultaneouslyactuating said functioning means actuating solenoid, switch meansautomatically actuated by the reciprocatable means for completing thecircuit to simultaneously actuate said magnetic switch to actuate aslidable valve actuating solenoid and said functioning means solenoid atsubstantially the ends of the reciprocatable means strokes, and switchmeans actuated by the valve at substantially the completion of itschange of position to break said circuit.

3. In a machine tool, in combination, reciprocatable means,reciprocating means therefor,` fluid-operated system means forreciprocating said reciprocatable means including auni-directional pump,valve means to reverse the fluid ow to reverse the direction of motionof said reciprocating means, electromagnetic means having a movable partoperatively connected to said fluid flow reversing valve, means forcontrolling said reversal, and switch means connected to saidelectromagnetic means and adapted to be actuated by said reciprocatablemeans at substantially the ends of the reciprocatable means strokes toactuate said electrical control means to reverse the direction of fluidow 'and hence of reciprocation.

4. In a machine tool, in combination, reciprocatable means,reciprocating means therefor, electromagnetic means having a movablepart for controlling the reversal of said reciprocating means, switchmeans electrically connected to said electromagnet means andelectrically actuated by said reciprocatable means at substantially theends of the reciprocatable means strokes to actuate said electromagneticmeans movable part to reverse the direction of reciprocation and meanscooperating with said movable part to control the speed thereof to'determine the duration of dwell during reversal.

5. In a machine tool, in combination, reciprocatable means,reciprocating means therefor, solenoid means having a movable part forcontrolling the reversal of said reciprocating means, switch meanselectrically connected to said solenoid means and actuated by saidreciprocatable means at substantially the ends of the reciproca'fablemeans strokes to electrically actuate said solenoid means to reverse thedirection of reciprocation, and an adjustable dashpot means cooperatingwith said movable part to adjustably control the speed thereof todetermine the duration of dwell during reversal.

6. In-a machine tool, in combination, reciprocatable meansT-meansmounted on said machine independently of said reciprocatable means tofunction with said reciprocatable means, one of said means being adaptedto carry work and the other to act upon said work, means for feedingsaid functioning means relative to said recipro- -catable means,electrical means including a circuit for controlling thev reversal ofsaid reciprocatable means and for moving said feeding means, saidelectrical means having a movable part, current-actuated means foractuating said electrical means electrically connected by said circuitto said electrical means, switch means connected to saidcurrent-actuated means and actuated by said reciprocatable meansat-substantially the ends of the reciprocatable means normal strokes toinitiate current through said current-actuted means to actuate saidelectrical means to reverse said reciprocatable means and means to shutolf said electric current actuated by said first-mentioned electricalVmeans movable part after completion of its movement effecting reversalof said reciprocatable means, and means `cooperating with Asaid movablepart to control 5 the speed thereof to determine the duration of dwellduring reversal, whereby said feeding means may be completely actuatedduring said dwell, and limit switches in said circuit spaced beyond thenormal strokes of said reciprocatable means 10 adaptedto break saidcircuit to stop any abnormal motion of said reciprocatable means.

7. In a machine tool, in combination, reciprocatable means, meansmounted cn said machine independently of said reciprocatable means 15 tofunction with said reciprocatable means, one of said means being adaptedto carry work and the other to act upon said work, means for feedingsaid functioning means relative to said reciprocatable means, electricalmeans for control- 20 ling the reversalof said reciprocatable means' andfor moving said feeding means, said electrical means having a movablepart, switch means connected to said electrical means' and actuated bysaid reciprocatable means at substantially the 25 ends of saidreciprocatable means strokes to actuate said electrical means tosimultaneously feed said functioning means and to reverse saidreciprocatable means, and means cooperating with said movable part tocontrol the speed thereof 30 to determine the duration of dwell duringthe reversal of said reciprocatable means, whereby said feeding meansmay be completely actuated during said dwell.

8. In a machine tool, in combination, recipro- 35 catable means,reciprocating means therefor, electromagnetic means having a movable-part for controlling the reversal of said reciprocating means,current-actuated means for actuating said electromagnetic meanselectrically connect- 40 ed to said electromagnetic means movable part,switch means connected to said current-actuated means and electricallyactuated by said reciprocatable means at substantially the ends of thereciprocatable means strokes to initiate current 45 through saidcurrent-actuated means to actuate said electromagnetic means movablepart, to reverse said reciprocating means and means to shut off saidelectric current actuated by said firstmentioned electromagnetic meansmovable part 50 after completion of its movement effecting reversal ofsaid reciprocating means.

9. In a machine tool, continuously reciprocatable means, means mountedon said machine independently of the reciprocatable means to func- 55tion therewith, one of said means being adapted rocating said.reciprocatable means including means to reverse the uid flow to reversethe direction of lmotion'of said reciprocating means, 70electro-magnetic means having a movable part operatively connected tosaid iiuid-iiow reversing means for controlling said reversal and switchmeans electrically connected to `said electromagnetic means and adaptedto be electrically actu- 75 ated byv said reciprocatable means atsubstantially the ends of the reciprocatable means strokes to actuatesaid electromagnetic control means to reverse the direction of iluidlllow and hence of reciprocation.

11. In a machine tool, in combination, reciprocatable means,fluid-operated means for reciprocating said reciprocatable meansincluding means to reverse the fluid flow to reverse thedirection ofmotion of'said reciprocating means, electrical means having a movablepart operatively connected to said iiuid ow reversing means forcontrolling the reversal of said iluidoperated reciprocatable means,switch means connected to said electrical means and adapted to beactuated by said reciprocatable means at Asubstantially the ends of theyreciprocatable means strokes to actuate said electrical means toreverse the direction of iluid ilow and hence of reciprocation, andmeans cooperating with said movable part to control the speed thereof todetermine the duration of dwell during reversal of said reciprocalmeans.

12. In a machine tool, in combination, reciprocatable means;Huid-operated system means for reciprocating said reciprocatable meansincluding a uni-directional pump, valve means to reverse the fluid iiowto'reverse the direction of motion of said reciprocating means, means tovary the speed of iluid flow, and a pressure-relief valve releasable onan excess pressure in said system; electrical means having amovable-part operatively connected to said fluid flow reversing Valve,means forcontrolling said reversal, switch means connected to saidelectrical means and adapted to be actuated by said reciprocatable meansat substantially the ends of the reciprocatable means strokes to actuatesaid electrical control means to reverse the direction of uid ilow andhence of reciprocation and a unitary manually controlled by-pass andswitch means for interrupting the iiow of fluid through said system tostop. said reciprocatable means at any desired portion of itsreclprocation cycle and simultaneously shut oif the current in saidelectric means.

13. In a machine tool in combination reciprocatable means, piston andcylinder Huid-operated means having different eiective areas at oppositeends thereof for reciprocating said reciprocatable means including meansto reverse the uid oW to reverse the direction of motion of saidreciprocating means, solenoid means having a movable part operativelyconnected to said fluid ow reversing means 4for controlling the reversalof said fluid-operated reciprocatable means, switch means connected tosaid electrical means and adapted to be actuated Vby said reciprocatablemeans at substantially the ends of the recip rocatable means strokes toactuate said electrical means to reverse the direction of fluid flow andhence of reciprocation, and means cooperating with said movable partadjustable to control the speed thereof in each direction duringreversal of said reciprocatable means to compensate for said diierenceof eifective areas of said piston and cylinder means. 1

14. In a machine tool, in combination, recip-` rocatable means, pistonand cylinder fluid-oper-v ated means having different effective areas atopposite ends thereof for reciprocating said reciprocatable meansincluding means to reverse the fluid flow to reverse the direction ofmotion of said reciprocating means, means to vary the speed of fluidilow and a pressure-relief valve releasable on an excess pressure insaid system; electrical means including a circuit' and having a movablepart operatively connected to said iluid-flow reversing means forcontrolling the reversal of said fluid-operated reciprocatable 'meansover a normal path, means mounted on said machine independently of saidreciprocatable means to function with said reciprocatable means, one ofsaid means being adapted to carry work and the other to act upon saidwork, means for feeding said functioning means relative to saidreciprocatable means; switch means connected to said electrical meansand adapted to be actuated by said reciprocatable means at substantiallythe ends of the reciprocatable means strokes to simultaneously actuatesaid -feeding means and said electrical means to reverse the directionof iluid-flow and hence of reciprocation, and means cooperating withsaid movable part adjustable to control the speed thereof in eachdirection during reversal of said reciprocatable means to compensate forsaid difference of eiective areas of said piston; and a manuallycontrolled by-pass for interrupting the ow of uid through said system tostop said reciprocatable means at any desired portion of itsreciprocation cycle and simultaneously shut oi the lcurrent in saidelectric means; and limit switches in said circuit spaced beyond thenormal path of said-reciprocatable means adapted to break said circuitto stop any abnormal motion of said reciprocatable means.

15. In a machine tool, in combination, reciprocatable means,reciprocating. means therefor, a permeable core, two oppositely disposedsolenoids co-actable therewith, each for controlling the reciprocationsof said reciprocating' means in its respective direction, an electriccircuit to actuate said solenoids including a. magnetic switch foralternately operating said solenoids, switch means automaticallyactuated by said to actuate said magnetic switch to electrically,actuate the respective one of said solenoids at substantially the endsof the reciprocatable means strokes,A and switch means actuated by saidsolenoid operated core at substantially the completion of each change ofits position to break said circuit.

16. In a machine tool organization the combination of a. support, amember translatable thereover, hydraulic means for eiecting saidtranslationincluding a hydraulic medium and a conduit therefor, areversing valve for controlling the direction of flow of the mediumthrough the conduit, magnetic means for eiecting the reversal of thevalve, a reversing lever pivotally mounted on the support operable bythe table, and means operable by the lever for energizing the magneticmeans.

GEORGE T. HCDKFORD. FRANK E. STRATTON. PAUL G. HENEMANN.

reciprocatable means for completing the circuit GERTIFICATE OFCORRECTION.

atene No. 2,021,066. November 12, 1935.

GEORGE T. HUXFORD, AL.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows; Page 5,second column, line 'T5-74, for "oontuously" read continuously; page 5,first column, line 11-12, for "effects" read affects; line 25, for"re/sume" read resume; and line 66, for "diagrammatcally" readdiagrammatically; page 7, second column, line 41, claim 8, strike outvthe words "movable part" and insert the same after "means" in line 40,same claim; and that Y the said Letters Patent should be read vwiththese corrections therein that the same may conform to the record of thecase in the. Patent Office.

Signed and Sealed this 8th day of September, A. D. 1936.

Leslie Frazer Seal) I l Acting CommissionerI of Patents.,

